25 БАЛЛОВ ТОМУ КТО Досконально РЕШИТ 3,4,5 ЗАДАНИЕ..

3. (x - 2x) - 7 (x - 2x) - 8 = 0

t - 7t - 8 = 0

t = 8

t = -1

x - 2x = 8

x - 2x = -1

x = 4

x = -2

x = 1

x = -2, x = 1, x = 4

4. (x - 3x + 1) * (x - 3x + 3) = 3

x = 3x + 3x - 3x + 9x - 9x + x -3x + 3 = 3

x = 3x + 3x - 3x + 9x - 9x + x -3x = 0

x - 6x + 13x - 12x = 0

x * (x - 6x + 13x - 12) = 0

x * (x - 3x - 3x + 9x + 4x - 12) = 0

x * (x * (x-3) - 3x * (x-3) + 4 (x-3)) = 0

x * (x-3) * (x - 3x + 4) = 0

x = 0

x - 3 = 0

x - 3x + 4 = 0

x = 0

x = 3

x R

x = 0

x = 3

x = 0, x = 3

5. (7x-2) - 12 * I7x - 2I - 28 = 0

t - 12 * ItI - 28 = 0

t  = 14

t = -14

7x - 2 = 14

7x - 2 = -14

x =

x =

x = , x =

3)
(х-2х)=t
t-7t-8=0
d=7+4*8=49+32=91
81=9
t1=(7+9/2)=16/2=8
t2=(7-9/2)=-2/2=-1
4)
(x-3x+1)(x-3x+3)=3
x-3x+3x-3x+9x-9x+x-3x+3=x-6x+13x-12x=0
x(x-6x+13x-12)=0
x(x-3x-3x+9x+4x-12)=0
x(x(x-3)-3x(x-3)+4(x-3))=0
x(x-3)(x-3x+4)=0
x=0
x-3=0
x-3x+4=0
x=3
5)
t-12t-28=0
t-12t-28=0
t-12(-t)-28=0
d=12+4*28=144+112=256
256=16
t=(12-16/2)=-4/2=-2
t=(12+16/2)=28/2=14